Minami-rinkan, Japan
Minami-rinkan, Japan

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Osawa T.,University of Toyama | Kizawa T.,Metek Co. | Takano F.,University of Toyama | Ikeda S.,Metek Co. | And 4 more authors.
ChemCatChem | Year: 2014

The chirally modified nickel catalysts for the enantiodifferentiating hydrogenation of β-ketoesters are prepared conventionally by immersing hydrogen-activated metallic nickel into an aqueous solution of enantiopure tartaric acid, in which the preactivation of nickel is essential. Herein, we revealed that even commercially available nickel powders without any pretreatment can catalyze the enantiodifferentiating hydrogenation of β-ketoesters to give the corresponding β-hydroxyesters in quantitative yield and high enantioselectivity (up to 91 %) under optimized conditions. The immediate use of commercially available nickel powders and the reproducible high chemical and optical yields not only expand the scope of heterogeneous asymmetric catalysis but also pave the way for the practical application and industrial use of chirally modified nickel catalysts. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Osawa T.,University of Toyama | Kizawa T.,Metek Co. | Ikeda S.,Metek Co. | Kitamura T.,Metek Co. | And 3 more authors.
Tetrahedron Asymmetry | Year: 2014

Heterogeneous catalytic hydrogenation of acetoacetic acid esters over tartaric acid/NaBr-modified Ni powder was determined to be a critical function of the steric bulk of the ester moiety to afford quantitatively 3-hydroxybutyrate in 94% enantiomeric excess when ethyl and i-butyl esters are used, providing a facile route to optically active 3-hydroxybutyrates. © 2014 Elsevier Ltd. All rights reserved.

Metek Inc. | Date: 2013-01-17

Work holders, cylinders, pneumatic cylinders, hydraulic cylinders, chucks, precision punches, magnetic vises, hydraulic vises, machine parts, namely push rods, crank handles, hand wheels, adjustable handles.

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